3. Clare Hargreaves-
Norris
Epidermis
This is the outermost layer of the skin (the part that you can
see), it does not have a blood supply of its own and is made up
of 5 layers:
Horny layer – the outer layer of the skin, this is made up of
scale like cells which are continuously shed (corn flakes).
Clear layer- this is made up of small transparent cells through
which light can pass. This layer is only present in the palms of
the hands and soles of the feet.
Granular layer – this layer is usually 1-3 layers thick. The cells
have distinct granules and keratin is produced in this layer.
Prickle cell layer – this layer is 3-6 layers thick and the cells
are constantly dividing.
Germinating layer – a single basal layer of cells, that contain
the pigment melanin. The cells of the epidermis are produced
in this layer and have a distinct nuclei. These cells divide
continuously by a process known as mitosis.
4. Clare Hargreaves-
Norris
Diagram of a cross section of the
epidermis
Horny layer
Clear layer
Granular layer
Prickle cell layer
Germinating layer
5. Clare Hargreaves-
Norris
Dermis
This layer is often referred to as the true skin as it forms
the bulk of the skin. The dermis contains 2 layers:
Papillary Layer – lies directly under the epidermis, it is
quite thin and has cone like projections called papillae. It
provides nutrients and oxygen to the germinating layer of
the epidermis
Reticular Layer – this lies below the papillary layer and is
the main portion of the dermis. Within the reticular layer
are collagen and elastin fibres. Collagen gives the skin a
plump and youthful appearance and is a white fibrous tissue
made up of proteins. Elastin gives the skin its elastic
properties and is made up of yellow elastic tissue.
Within the dermis are various other structures known as
appendages.
6. Clare Hargreaves-
Norris
Subcutaneous layer
This is located under the dermis and is
mainly made up of fat cells (adipose
tissue). This fatty layer of the skin
provides the plump contours of the body,
protection, insulation, support and a food
supply if needed.
7. Clare Hargreaves-
Norris
Papillary layer
of dermis
Sebaceous
gland
Nerve ending
Hair
follicle
Arrector pili
muscle
Subcutaneous
layer
Reticular
layer of
dermis
Sweat
gland
Dermal
papilla
Blood
supply
Hair shaft
Epidermis
Label your diagram of the cross section of the skin.
9. Clare Hargreaves-
Norris
Sweat glands
The sweat glands, which are sometimes referred to as the
suderiferous glands, extend from the epidermis into the
dermis and are found all over the body, however they are
particularly numerous in the palms of the hands and the
soles of the feet They regulate the body temperature by
allowing sweat to evaporate from the body.
There are two different types of sweat glands:
Eccrine glands – are found all over the body and secrete a
watery fluid.
Apocrine glands – are found in the underarms, nipple and
groin area and become active at puberty. They secrete a
thicker fluid that contains urea, fats, sugars and a small
amount of protein. Body odour can occur when bacteria
starts to break down the sweat.
11. Clare Hargreaves-
Norris
Hair shaft
The hair shaft is the portion of the hair
that lies above the skins surface. It is the
visible part that you see such as the
eyebrows, eyelashes, body hair and the
hair on the head.
12. Clare Hargreaves-
Norris
Blood supply
Blood is supplied to the skin by small blood
vessels known as blood capillaries. All parts of
our body require a blood supply as it provides the
vital oxygen and nutrients that tissues require in
order to survive. The capillaries also remove
waste products and toxins from the tissues. In
addition, the capillaries also help to maintain the
body temperature by dilating (widening) and
constricting (narrowing).
13. Clare Hargreaves-
Norris
Dermal papilla
The dermal papilla is the blood supply for
the hair and its follicle. It provides food
and oxygen, which are essential for the
growth of the hair. The dermal papilla is a
separate organ that serves the follicle; it
is not part of the hair.
14. Clare Hargreaves-
Norris
Arrector Pili Muscle
This muscle is attached to the hair follicle
and it contracts when you are cold or
frightened causing the hair to stand up on
end. This action traps a layer of warm air
around the body to keep the body warm.
When the muscles contracts it pulls on the
skin around the follicle opening therefore
producing goose pimples
15. Clare Hargreaves-
Norris
Sebaceous glands
These glands are found all over the body except
for the palms of the hands and the soles of the
feet and produce the natural oil of the skin -
sebum. The sebaceous glands become more
active at puberty due to the increased levels of
androgens (male hormone) being produced. Men
generally secrete more sebum then women, and
you will usually note that the sebaceous glands
become less active as we get older.
Sebum is bactericidal and fungicidal and so
prevents against infection, it also provides
protection and prevents the skin from drying out.
16. Clare Hargreaves-
Norris
Nerve endings
Sensory nerve endings are found in the skin and
detect changes in the environment such as heat,
cold, touch, pain and pressure. There are
different nerve endings that detect the
different sensations. Sensory nerve endings send
messages to our brain to let us know what we are
feeling.
Motor nerves bring messages from our brain to
bring about a response.
